This application is in response to NIH Program Announcement 03 161 "Research on the reduction and prevention of suicidality" that was co-sponsored by NIAAA. Individuals with alcohol dependence are at high risk for both attempted and completed suicide. Patients in intensive treatment for alcoholism are at especially high risk. The purpose of this project is to enhance understanding of suicidal behavior among patients seeking treatment for alcohol dependence both by illuminating major differences between suicidal and non-suicidal individuals as well as by examining sources of heterogeneity within attempters. In Aim 1, the roles of reactive and proactive aggression in attempted suicide are examined, and in Aim 2, the focus is on the experience of aloneness, assessed objectively as living alone and subjectively as "loneliness." In Aim 3, a model of suicide planning that incorporates these variables is evaluated that posits reactive aggression and acute interpersonal difficulties (e.g., partner relationship break-ups) lead to low-planned (impulsive) suicide attempts in this population whereas depression and aloneness create the conditions for high-planned attempts. The aims are carried out using a retrospective case-control study design. Subjects in inpatient treatment for alcohol dependence who have made a suicide attempt within 90 days of treatment are identified using a uniform screen and followed up with a detailed research interview about the act of suicide, its circumstances, and hypothesized risk factors (e.g., reactive aggression). Non-attempter controls are recruited for comparison. Subjects include 40% women, 39% black individuals, and most are economically disadvantaged. Data on severity of alcohol dependence and other drug use are obtained, and accounted for in all analyses. Multivariate logistic regression analyses are used to compare cases and controls in Aims 1 and 2, and multivariate linear regression analyses of cases assessed on a continuum of level of planning of the attempt are used in Aim 3. Patterns related to age, gender, and race are also explored. Results may advance research on suicide and alcoholism focused on the reactive aggression phenotype, underscore the critical need to consider the interpersonal life of individuals seeking treatment for alcoholism who may be at risk for suicide, and inform treatments that seek to identify and affect the course of low-planned and high-planned suicidal behavior in this population.